Field of the Disclosure
The present disclosure relates to a robot cleaner and a control method for the same.
Description of the Related Art
Robots have been developed to be used in industries to contribute to a part of factory automation. Recently, with expansion of robotics, medical robots and aerospace robots have been developed, and robots which can be used at home have also been developed. Among such robots, robots capable of autonomously traveling are referred to as mobile robots.
A typical example of mobile robots for home use is a robot cleaner. The robot cleaner is a home appliance that performs cleaning operation by suctioning dust or debris while moving about an area to be cleaned. The robot cleaner is capable of autonomously traveling since it is provided with a rechargeable battery. When remaining battery life is insufficient for operation, or cleaning is completed, the robot cleaner autonomously moves to a charging base and recharges the battery.
Conventionally, the robot cleaner searches for a charging base by sensing, through an infrared sensor, an infrared (IR) signal transmitted from the charging base. Moreover, various methods for the robot cleaner to create a map of a cleaning area based on surrounding information retrieved during travel are known. The created map contains information about the position of the charging base.
When recharging is needed, the robot cleaner needs to accurately recognize the position thereof on the map in order to correctly return to the charging base. Accordingly, in the case in which the position of the moving robot cleaner is forcibly changed by an external factor (for example, in a case in which a user moves the moving robot cleaner to another room), the robot cleaner cannot recognize the position thereof on a currently created map or a previously created map. As a result, the robot cleaner cannot return to the charging base. In this case, the robot cleaner searches for the IR signal transmitted from the charging base at the current position again. However, if the robot cleaner performs search for the charging base without knowing the position thereof as in the above example, it may sense the signal by chance, but in most cases, it runs out of battery, while wandering around searching for the signal. This problem also occurs when the robot clear creates a map of surroundings again at the moved position. As long as the robot cleaner fails to recognize the position thereof on the map of the entire cleaning area, return to the charging base raises a question of whether or not the signal transmitted from the charging base can be detected at the changed position and still depends on trial and error. Therefore, a global localization method with which the robot cleaner can recognize the current position thereof on a whole map is needed.
The problem of failure to return to the charging base described above is an example of problems that may occur in a robot cleaner which is not provided with a function of global localization. Various other problems may occur in such robot cleaner. For example, recently, a technology of setting the cleaning range using a terminal (e.g., a remote control, a smartphone, etc.) that communicates with the robot cleaner over a network is increasingly widely used. Even in this case, setting the cleaning range through a terminal may be accurately performed only when the cleaning range is based on global localization.